Syria conflict: Annan warns 'all-out war' approaching
Syria is slipping closer to all-out war with each passing day, the UN peace envoy Kofi Annan has warned.
Mr Annan, in Doha for a meeting with Arab League members, warned that the conflict was developing an alarming sectarian dimension.
Qatar urged the UN to set a deadline for Mr Annan's peace plan, saying there should be no more "stalling".
Syrian opposition groups said Russia was becoming part of the problem by supporting President Bashar al-Assad.
"The spectre of all-out civil war, with a worrying sectarian dimension, grows by the day," Mr Annan said.
He said that the massacre at Houla, in which 108 people were killed, many of them women and children, was appalling and that the crisis was now at "tipping point".
The UN Human Rights Council approved an investigation into the mass killing last week.
Mr Annan, who admitted that his six-point plan had failed to stop the violence, expressed frustration with the Syrian president for not matching words with actions.
This was the starkest warning yet from Mr Annan, as he continues to urge the Syrian leadership to take what he calls "bold steps" on the ground to show that its serious about reaching a peace agreement.
Earlier, in Beirut on Friday, he had expressed his frustration and impatience, and made it clear that his mission was not open-ended.
He is under pressure from Qatar and other Arab states who want to see the Assad regime fall, to set a cut-off point at which he would declare his peace plan a failure.
The Syrian opposition, and especially the rebel Free Syrian Army, are also wary that his mission may simply be buying time for the regime.
He urged the international community not to forget that the conflict risked spilling over.
It was vital, he said, "to keep our goals firmly in view: stopping the killing, helping the suffering population, securing a political transition - and, I would add, ensuring that the crisis does not spread to the neighbours".
Meanwhile reports from northern Lebanon on Saturday said at least seven people had been killed and 20 wounded in clashes between Lebanese supporters and opponents of the Syrian regime in the port city of Tripoli.
In Syria itself, opposition activists reported that there was more violence on Saturday.
Two civilians were killed - one during an army raid in the capital, Damascus and another by gunfire in the city of Homs.
The British-based Syrian Observatory for Human Rights also said that rebels had killed six soldiers in the southern province of Deraa and at least eight others in clashes on the outskirts of Damascus.
Burhan Ghalioun, of the Syrian National Council - the divided body which says it represents the political opposition to Mr Assad - said Russia was standing in the way of progress.
"With its support of the regime and for Assad remaining, Russia has become part of the problem rather than part of the solution," he said.
"If it co-operates to find a formula that makes Assad leave, it will become part of the solution."
Russia's President Vladimir Putin has resisted diplomatic pressure to support tougher action against Syria's government, calling for more time to be given to Mr Annan's plan.
The country voted against the recent US-backed human rights council resolution, arguing that it was "unbalanced".
Meanwhile, Prime Minister Sheikh Hamad bin Jassim al-Thani of Qatar said a time limit should be set for Mr Annan's mission - which began three months ago.
He also called for it to fall under Chapter 7 of the UN charter, enabling the use of force.
"We, the international community, cannot accept the situation to continue as it is," he said.